Mid-rotation fertilization and liming of Pinus taeda: growth, litter, fine root mass, and elemental composition

Abstract

Biogeosciences and Forestry Biogeosciences and ForestryMid-rotation fertilization and liming of Pinus taeda: growth, litter, fine root mass, and elemental composition William Magrim Adam (1) , Valdécio Dos Santos Rodrigues (2) , Ederlan Magri (2) , Antônio Carlos Motta Vargas (2) , Stephen A Prior (3) , Leandro Moraes Zambon (4) , Rubia Luciane Dominschek Lima (2)Forest floor litter can influence biogeochemical cycling and root growth in Pinus taeda systems, especially on low soil fertility sites. The impact of fertilization and liming on forest floor litter (quantity, elemental composition and root presence) was evaluated in a Pinus taeda stand in southern Brazil. A nutrient omission experiment was initiated in November 2008 on an 11 year-old Pinus taeda plantation. The experiment was a randomized block design with seven treatments and four blocks. The treatments were: complete (macro + micro + lime); minus macronutrients; minus micronutrients; minus K; minus Zn; minus lime; and control. In 2012, forest floor litter samples were collected, divided by layer (new litter, old litter, coarse fragmented forest layer > 2mm, fine fragment forest floor < 2mm, and fine roots) and analyzed for concentrations of Na, Al, and total nutrients. Results indicated that lime increased Ca and Mg concentrations, reduced Al toxicity, and improved fine root growth. An increase in fine roots was observed in treatments without K. There were large increases in Fe and Al as a function of litter age and increased Mn in fragmented litter when lime was applied. There was little variation in forest floor litter accumulation in all treatments. Elemental abundance was C>N>Fe>P> Ca>K>Mg>Mn under control conditions and C>N>Ca>Mg>P>Fe>Mn>K for the complete treatment. Occurrence of needle chlorosis, similar to that reported for Mg, and low growth under lime omission indicate that Mg was a major factor limiting growth. Fertilization and liming affected the bio-cycling of nutrients, Al toxicity, and root growth.

Wood production and nutritional status of Pinus taeda L. in response to fertilization and liming: a meta-analysis of the Americas

“…A significant increase in wood production of loblolly pine in response to fertilization, as revealed in the present study and supported by findings of multiple studies (Fox et al 2007, Carlson et al 2014, Adam et al 2021, Pereira et al 2022, occurs due to a series of effects related to the improvement of plant nutrition and belowground and aboveground growth. Fertilization favored enhanced root growth probably due to improved nutritional status (Alvarez-Clare & Mack 2015, Consalter et al 2021a.…”

“…In a 16-year-old forest, Albaugh et al (2004) found increases of 100% and 130 % in total aboveground and belowground biomass, respectively; this corroborates findings obtained in the present study. In addition to the direct effect of nutrients, the Ca/Al ratio of roots can also influence root growth in response to fertilizer and limestone use (Adam et al 2021). Thus, a more vigorous loblolly pine root system translates into greater water and nutrient acquisition efficiencies, which along with higher nutrient supply via fertilization and liming, contributes to greater aboveground growth (in relation to height and trunk diameter) that favors wood production.…”

“…Use of limestone and alkaline organic residues to elevate soil pH and supply of calcium (Ca) and magnesium (Mg) has been evaluated since Mg deficiency (associated with or without Ca deficiencies) has been reported for pines in the USA and Brazil (Chaves & Corrêa 2005, Rocha et al 2019, Adam et al 2021. Alkaline residues may also contain several macro-and micronutrients that increase the possibility of pine responses (Rodriguez et al 2018, Sass et al 2020, Rabel et al 2021).…”

“…Mid-rotation fertilization can favor greater growth of trees with ample root systems and absorption capacity. The formation and accumulation of litter following nutrient and corrective applications can allow for retention within this horizon, thereby contributing to sources of Cu, Zn, and soil acidity correctives (Adam et al 2021).…”

Relationship between microbiological, physical, and chemical attributes of different soil types under Pinus taeda plantations in southern Brazil

“…Silvicultural management in forest plantations can increase tree growth in P. taeda plantations, especially in the long term, through the contribution of forest residues from previous harvest crops (Adam et al 2021). We hypothesized that the microbial activity in the soil of P. taeda plantations is correlated to some physical and chemical attributes resulting from the soil pedogenesis as well as from the soil and silvicultural management.…”